Readily cleanable dual purpose water storage system and method

ABSTRACT

A water storage system comprising a tank having a first inclined or conical floor at the bottom of the tank, a second inclined or conical floor above the first inclined or conical floor, dividing the tank into upper and lower compartments, one or more inlet(s), an overflow outlet, a first draining outlet located at the sloping end of the first inclined floor or at the convergence of the first conical floor, a second draining outlet located at the sloping end of the second inclined floor or at the convergence of the second conical floor, and a consumer supply outlet located above the second inclined floor or above the second conical floor, wherein the upper compartment holds potable-grade water and the water from the lower compartment is reserved for fire fighting needs and used for non-potable purposes with periodic replenishment from upper compartment

CROSS REFERENCE

This application is a continuation-in-part of application Ser. No.13/383,013 filed on 9 Jan. 2012.

FIELD OF THE INVENTION

This invention relates to a readily cleanable water storage system andparticularly an improved water storage tank for this system and methodof regular cleaning thereof by which high level of cleanliness of watercan be maintained with considerable ease in a cost effective manner.This invention further relates to a dual purpose water tank wherein thewater content of the lower portion of the tank is kept constantlyreserved for use in sprinklers for fire fighting operations and thewater content of the upper portion is used for supply of potable gradewater to consumers.

BACKGROUND OF THE INVENTION

Storage of water is essential before distribution to the consumerthrough a pipeline. To this end, water tanks of various sizes and kindsare used. Tanks made out of metal, brick and mortar are now giving wayto those of plastic or synthetic materials due to various reasons likecost effectiveness, ease of installation and maintenance,non-susceptibility to leakages, etc. Wooden water tanks are also in usein certain regions of the world.

However, one cause of concern in all kinds of water tanks currentlyavailable is its poor level of cleanliness and that of its contents.Water entering the tank from the city's water source invariably containssome foreign matters. Over a period of time the foreign matters in theform of suspended impurities settles to the bottom of the tank andrequires periodic cleaning. It is not unusual for a tank to accumulateanywhere up to an inch or so of muddy sediments over a period of time, aresidue that pose severe health hazard for the consumers.

Water tanks have not changed much during the past hundred years or so.Some of the techniques used in their construction have been improvedresulting in shorter manufacturing and installation time, but theoverall principle of water tanks remains unchanged.

Conventional water tanks in use are either rectangular or cylindrical inshape in general and the outlet for supply of water to consumers is at apoint on its sidewall slightly above its bottom. This point is so chosenso as to allow all the suspended contaminants, dirt and muddy substancesin the water to settle down on the bottom surface that do not pass intothe supply outlet located above the deposited sediments. Theseimpurities some of which hang in the water content keep on depositing onthe floor of the tank turning into a sludge over a period of time, whichrequire to be thoroughly scrubbed in order to dislodge it effectively.This cleaning is an elaborate process requiring some preparation andstoppage of water supply to the consumers for a considerable period.Considerable time and effort is spent in scrubbing out those stickydeposited materials. Since the outlet from the tank is a bit above thebottom, all the scrubbed material along with water remaining below thisoutlet requires to be lifted and thrown out with the help of buckets,mugs, or by other means. This is followed by sponge drying anddisinfecting of the bottom surface and inside walls of the tank. Allthis is a lengthy and cumbersome process and still does not assure aconstantly high level of cleanliness. Further, it may leave scratches onthe inside surfaces of the tank that may corrode the tank progressively.Also, the lengthiness of the process tends to reduce its frequency,thereby compelling the consumers to consume harmful contaminated waterindefinitely.

During the daily chore of filling of tank, the falling mass of waterinside the tank dislodges part of the said layer of sediments from thefloor and this material rises above to dance and revolve with theagitated mass of water. This continues till the filling of waterprogresses. It also settles partly on the side walls of the tank therebydirtying them as well. Most of these foreign matters remain in asuspended state owing to buoyancy for considerable time and continue topass on to the supply route away from the tank. Till such time the usersare forced to continue consuming such contaminated water for varioususes in the bath, kitchen, washing, etc., and for drinking. Also, a partof the impurities and dirt, which is soluble, gets dissolved during theswirling agitation of water and may not be detected visually. All thismake the supplied water a carrier of impurities which gets thicker anddenser with every passing day and good part of it is also deposited onthe inside wall of the water supply line thereby reducing the flow ratewith passage of time. This is a compulsion everyone lives with which isnot realized because the dirty scene of action happens to be away in theclosed tank at the top of the building and one cannot make out dirtinessby simply looking at the water at the receiving end.

It is true that some people keep water filters at the users' end inorder to get clean potable water. But there are again several factorsthat decide the quality of water one gets from it. These may be likequality assurance associated with that filter, whether that filter isproperly maintained or not with timely replacement of cartridges,candles, etc. Again, water filters are primarily used for the purpose ofdrinking water only. Bulk of the water supply is directly used duringbathing, brushing teeth, washing mouth after meals, food preparation,etc. Therefore, one still remains vulnerable to the dirty water comingfrom the supply route from that overhead tank.

So, a vast majority of human population, with the exception of thosepeople who live in remote areas where such tanks are not used forstorage of potable water, has no way but to consume such contaminatedwater.

Potable water is a basic necessity of life and deserves the same levelof care, cleanliness and respect as any other food item. Every utensilhandling food items is given a complete washing in dishwasher ormanually and in the same fashion the water storage tank should bemaintained with complete renewal of stored water regularly. This doesnot happen in the conventional tank and total cleanliness is erroneouslypresumed. With every filling of the tank, certain amount of stale waterremains in the bottom along with those muddy sediments. It is happeningdespite countless people being involved in the business of storage watertank right from design and manufacture, distribution and dealers'network to plumbing and installation and finally to end users. Also,there is a vast network of tank maintenance and cleaning companies andestablishments which specialize in the expertise of tank cleaning. Thesepeople follow elaborate processes for the job and charge substantially.In spite of the involvement of technical people, the scenario remainsthe same.

So, an urgent solution was needed so that the regular renewal of thewater content in the tank is possible in order to ensure a highcleanliness level of water within the tank in a cost effective,convenient and time-saving manner.

The objective of this invention is to present a solution in the shape ofan improved design of a water tank and a method of cleaning the samewhich ensures a comparatively much higher level of cleanliness of waterfor the consumers. It ensures complete renewal of the water content ofthe tank in an extremely convenient method which can be carried outregularly and swiftly with utmost ease in a cost effective manner.

Another objective of this invention is to provide a dual purpose watertank wherein the water content of the lower portion of the tank is keptconstantly reserved for non-potable use in sprinklers for fire fightingoperations and the water content of the upper portion is used for supplyof potable grade water to consumers with rest of water content gettingconstantly renewed.

SUMMARY OF THE INVENTION

The present invention mainly lies in the shape of a water tank whichappears more or less similar to conventional water tank from the outsideexcept for the bottom side. The tank may be of cylindrical, rectangularor any other shape and may be made of any material. The major differencelies in the inside bottom of the proposed tank which is inclined with acontinuous effective slope so that all the water inside rushes down theslope of the inclined or conical bottom. It has an outlet for completedrain out of water from the said inclined or conical bottom of the tank.This outlet, which may be located anywhere along the periphery at thesloping end of the floor or at the convergence of the cone for a tankwith conical bottom, is meant for draining out the water inside the tankcompletely whenever desired. This draining outlet may be extendedthrough extra pipeline to a convenient place and a stop cock provided atthat point to discontinue the discharge of water from drainage outlet.Alternatively, a drainage outlet is provided with electronicallyoperated stopping means that can be remotely controlled for convenienceof the cleaning operation. When the said draining outlet is opened, thewater from inside the tank starts flowing out and as the water levelapproaches the bottom of the tank, all of it rushes towards the saidexit at the lowest point as no water can remain on the slant surface ofthe bottom. The draining outlet at the lowest point of slope should nothave any protrusions or edges towards the inside, which may obstructexit of the sediments, impurities, etc. The mouth of the draining outletshould have a smooth converging easy curvature for uninterrupted flow ofdrainage water therethrough. Bend sections in extended pipeline may bekept at a minimum.

Eventually the tank empties by itself without any special effort madefor the purpose in contrast with the conventional tank which requirescleaning personnel to go physically inside and lift water from thebottom with considerable effort. All the sediments and other foreignmatter also rush out through the said draining outlet without anyexternal action involved. After the tank empties itself on its own, thewater inlet for filling the tank is opened. Water starts falling on thesaid inclined bottom of the tank which further cleans the bottom andflushes further dirt, if any, towards the said draining outlet and isdrained out. Some time is allowed for this process to continue beforethe said draining outlet is closed and water filling in the tank startsfor storage. The outlet for supply to consumers is fixed at a pointhigher than the said bottom of tank described above so that only cleanwater goes into the supply line. Therefore, the consumers do not get anycontaminated water as in the case of conventional tanks wherein all thesediments and impurities continue to accumulate progressively at thebottom with passage of time that contaminates the water in the supplyline as discussed above.

There may appear a wastage of a small amount of water mass which liesbetween the said supply outlet and the draining outlet in the process ofthis complete renewal of water. This is only notional, because thiswater can be directed towards some other utilities where potable gradewater is not required, like floor and other type of cleanings,gardening, watering of plants and trees, washing of vehicles, etc.

In one embodiment of the present invention it provides a readilycleanable water storage system with a water tank having an inclined orconical bottom with a continuous and effective slope which automaticallyrushes all the water content towards the draining outlet located at theend of the said slope or at the convergence of the cone of the conicalbottom. The supply outlet for consumers is located at a point well abovethe draining outlet.

The said draining outlet is optionally extended to a place convenientfor the user to operate and a stopping mechanism provided at that pointso that the operator can close or open the said draining outlet fromthat point whenever required. Alternatively, an electronicallycontrolled stopping means can be provided closer to the water tank, witha remote control switch available with the operator for an easyoperation especially in case of taller buildings where extending thedraining outlet by extra pipeline may not be cost effective or remaintrouble-free.

The tank may be emptied regularly/daily or preferably before everyfilling by opening the said draining outlet, some fresh water allowedthrough the inlet and allowed to drain out and then fresh water storedby closing the draining outlet.

The small amount of tank water which comes out of the draining outlet,during periodic renewal of water in the tank, may be optionally directedtowards non potable usage thereby saving water from wastage, even duringthe periodic renewal of water in the tank.

The present invention in one embodiment thus provides a readilycleanable water storage system comprising: an overhead water tank forstoring potable and other kind of water, wherein said water tankcomprises: a floor, at least one inlet for letting water to be filledinto said tank, a draining outlet with a stop cock fitted thereto, anoverflow outlet, and a consumer supply outlet through which water issupplied to consumers and a pump for pumping water from a water supplysource at ground level to the overhead tank for storage of water beforesupply to consumers, characterized in that the floor of the tank isinclined at a pre-determined continuous and effective slope eithertowards another point on the periphery to form an inclined floor or fromall sides to form a conical bottom and the draining outlet is located atthe periphery of the inclined floor at the sloping end or at theconvergence of the cone formed by the conical bottom, as the case maybe, in order to completely discharge the water stored in the tank whenthe draining outlet is opened.

The draining outlet may be optionally extended to a place convenient forthe user to operate and a stopping mechanism provided at that point sothat the operator can dose or open said draining outlet from that point.A remote electronically controlled stopping mechanism may be providedcloser to the water tank, with the remote control switch available withthe operator for easy operation, particularly in taller buildings. Thestop cock or the remote control switch is preferably accessible andcapable of being operated from a lower floor of the building such asground floor by virtue of being fitted in an extended draining outletpipe closer to the level from which it is desired to be operated. Thestop cock or remote control switch for draining outlet is mostpreferably located close to the pump room housing the pump whichsupplies water to said tank. The supply outlet for consumers is locatedat the side wall at a point above the starting end of sloping floor ofthe tank and the water inlet is located at a point to discharge thewater near the starting end of the sloping floor of the tank.

The bottom of the water tank in one embodiment may be inclined from allthe sides to make a cone and the supply outlet can be located at theside wall of the tank preferably above the conical bottom of the tank. Adraining outlet pipe may be located at the point of convergence of thecone with the draining outlet pipe extending to a convenient place at alower floor preferably ground floor for cleaning of the water tankthrough a stop cock. The water inlet(s) is/are located so as todischarge the inlet water on the inclined surface(s) of the conicalbottom of the tank.

The present invention in another embodiment provides a method ofmaintaining cleanliness of water in the overhead tank of a water storagesystem wherein the overhead tank has a sloping floor or a conical bottomwith a drainage outlet at the periphery of the sloping floor at thesloping end or at the convergence of the cone forming the conical bottomcomprising the steps of (a) regularly draining out the water held in thetank by opening the stop cock of the draining outlet to completely emptythe tank; (b) opening the inlet of tank to dislodge any sediment ordeposit still adhering to the floor or bottom of the tank by letting inthe jet of one or more water inlet(s) from the water supply line andallowing it to fall on sloping floor or conical bottom of the tank whilekeeping the drainage outlet still open and (c) refilling the tank withfresh water from the supply inlet after dosing the drainage outlet aftersome time.

Water from the inlet falls directly on the impurities if any collectedat the bottom of the water tank such that those are easily dislodged.Occasionally, a sponge or cloth like cleaner or brush attached to a longhandle is used to rub out and clean the bottom and walls of the tank,followed by water being allowed to flow in the said tank for a fewminutes through draining outlet for final cleaning before closing thestop cock of the said draining outlet to hold fresh clean water in thetank. The tank may have a conical funnel shaped bottom and the dischargefrom the inlet is directed to different points on the inclined surfacesof the conical bottom of the tank by manipulating the inlets for pumpedwater in the tank.

The invention in one embodiment provides for separate outlet for takingout potable water for consumption from an upper level of the storedwater and also a sensor to actuate the pump for pumping fresh waterafter fall in water level to a predetermined level in the water tank,while water from the bottom outlet of inclined floor is diverted fornon-potable purposes.

The invention in another embodiment provides a second conical orinclined floor that separates the water tank into two compartments suchthat the water from the lower compartment is used for non-potablepurposes and the water from the upper compartment is used for potablepurposes.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

This invention is described below with the help of accompanying drawingsin which:—

FIG. 1 illustrates a conventional common rooftop water tank.

FIG. 1A illustrates another conventional water tank with a flat bottomhaving a sensor mechanism and the consumer outlet being located at alevel around the sensor mechanism.

FIG. 2 illustrates a water tank according to one embodiment of theinvention having an inclined bottom.

FIG. 2A illustrates a water tank according to one embodiment of theinvention having an inclined bottom, a sensor mechanism for refillingthe tank, and a consumer outlet being located at a level around thesensor mechanism.

FIG. 2B illustrates a water tank according to one embodiment of theinvention having a second inclined floor, located above a first inclinedfloor, the second inclined floor being provided at about the midway ofthe vertical height of the tank with a second draining outlet at thesloping end of the second inclined floor, for draining water below thesecond inclined floor down towards first inclined floor.

FIG. 2C illustrates a water tank according to one embodiment of theinvention having a second inclined floor, located above a first inclinedfloor, the second inclined floor being provided at about the midway ofthe vertical height of the tank with a second draining outlet at thesloping end of the second inclined floor for draining water below thesecond inclined floor, and a floating ball stopper to maintainunidirectional downward flow of water, and prevent mixing of waters ofthe two compartments created by the second inclined floor.

FIG. 3 illustrates a water tank according to another embodiment of theinvention with a draining facility which is more convenient to operate.

FIG. 4 illustrates a water tank according to yet another embodiment ofthe invention having a conical bottom with a draining facility which ismore convenient to operate.

FIG. 4A illustrates a water tank according to one embodiment of theinvention having a conical bottom, a sensor mechanism for refilling thetank, and a consumer outlet being located at a level around the sensormechanism.

FIG. 4B illustrates a water tank according to one embodiment of theinvention having a second conical floor, located above a first conicalfloor at the bottom of the tank, the second conical floor being providedat about the midway of the vertical height of the tank with a seconddraining outlet at the convergence of the second conical floor, fordraining water below the second conical floor.

FIG. 4C illustrates a water tank according to one embodiment of theinvention having a second conical floor, located above a first conicalfloor at the bottom of the tank, the second conical floor being providedat about the midway of the vertical height of the tank with a seconddraining outlet at the convergence of the second conical floor fordraining water below the second conical floor, and a floating ballstopper to maintain unidirectional flow of water and prevent mixing ofwaters of the two compartments created by the second conical floor.

FIG. 5 illustrates a water tank according to still another embodiment ofthe invention, wherein the water inlet(s) is/are located so as todischarge the inlet water at different points on the inclined surface(s)of the conical bottom of the tank.

FIG. 6 illustrates a water tank according to still another embodiment ofthe invention, wherein the water inlet(s) is/are located so as todischarge the inlet water at different points on the inclined surface ofthe bottom of a rectangular or cylindrical tank.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a conventional water tank 10 erected on the base 16commonly in use today wherein water is filled through the inlet pipe 11into the tank and the surplus water during the filling process exitsthrough overflow pipe 12. The outlet 14 is for consumer supply throughwhich water is sent to the consumers. The sediments and foreign matter15 that have deposited at the floor of the tank over a period of timecan be seen.

As shown in FIG. 1A, the conventional water tank may additionally have asensor mechanism 13 which activates the water filling mechanism (pump)whenever the water level falls down to a predetermined level forinjecting fresh water. The consumer supply outlet 14 are sometimesprovided to be near a level at which the sensor 13 operates to injectfresh water.

It can be seen that the scenario here promotes accumulation of dirt,impurities, sediments etc. in the water content because nearly half ofthe water content is always retained as stale water every time the tankis topped up by the water filling mechanism. During such operation,fresh water falls down on the stale water content, and all theimpurities and dirt get agitated and start moving around and dancingalong with the swirling water content. A vertical movement of water,dirt, impurities, germs, bacteria etc. may happen due to other factorstoo like temperature difference, heavier and lighter contaminants etc.Consumers receive their share of such contaminated waters along withthese impurities, as they open their taps. This is repeated everyday asthe dirt get multiplied progressively because a water reserve ofsomewhat like half of the tank's capacity is required to be maintainedalways and no complete evacuation can take place in this case.

FIG. 2 shows a preferred embodiment of the present invention in whichthe inclined floor 21 of the water tank 20 is shown and a drainingoutlet 22 with a stop cock (27) is located at a point at the end of theslope of the said inclined floor 21. The inlet 24 is meant for water tobe filled into the tank by a pump or other means with overflow outlet23. The consumer supply outlet 25 supplies water to its consumers. Theconsumer supply outlet 25 is located at a level just above the startingend of the inclined floor 21.

In another preferred embodiment of the present invention, as shown inFIG. 2A, the water tank, in addition to the one shown in FIG. 2 anddiscussed in the preceding paragraph, has a sensor mechanism 29 at aboutthe midway of the vertical height of the water tank, while the consumersupply outlet 25 is located near a level which is around the level ofthe sensor mechanism 29 which activate the pump to inject fresh water assoon as the level of water inside the tank falls below a pre-determinedlevel which is level of reserve to be maintained. The draining outlet 22is provided at the lowest point of the slope which may be extended andconnected to a network of secondary uses for non-potable purposes liketoilet cisterns, washing machines, floors and driveway cleanings,gardening etc. The sensor mechanism 29 is there to activate at the rightmoment to replenish whatever water mass finds way out of the drainingoutlet 22 and maintaining the reserve as per the requirement. Consumerscontinue to receive potable grade water through the consumer outlet nearthe mid-height of the tank. The water inlet 24 may be constructed withmultiple openings or pores so as to discharge jets of inlet water atdifferent points of the inclined floor 21 of the tank 20 thereby helpingto dislodge the impurities adhering to the bottom of the tank morereliably after switching off the sensor in case no reserve is required,thereby completely evacuating the water tank for cleaning purposes. Asubstantial improvement in level of cleanliness is achieved from thisarrangement in comparison with that of the conventional tank of FIG. 1and FIG. 1A because dirt and impurities do not get an opportunity toaccumulate but are let out through draining outlet 22 of the inclinedfloor progressively.

In another preferred embodiment of the present invention, as shown inFIG. 2B, the water tank, in addition to the first inclined floor at thebottom of the tank shown in FIG. 2A and discussed in the precedingparagraph, is provided with a second inclined floor 32 somewhere nearthe mid way of the vertical height of the water tank 20 but below thelevel of the sensor mechanism 29, which divides the tank broadly intotwo compartments, namely, upper compartment 33 and lower compartment 35,one above the other, but the second inclined floor 32 is located abovethe first inclined floor 21. The consumer supply outlet 25 is located ata level above the starting end of the second inclined floor 32. A seconddraining outlet 34, located at the sloping end of the second inclinedfloor 32 is capable of draining out completely the water content in theupper compartment 33 down to the lower compartment 35 so created. Thus,the vertical movement of water and impurities etc. is mostly curtailedto a minimum which can happen only through the second draining outlet34, which is an opening wide enough to simultaneously fill the lowercompartment to constantly maintain the reserve level therein. Thissecond draining outlet 34 may be just a simple opening, as shown in FIG.2B, or a check valve may be provided to allow only unidirectionaldownward flow. Alternatively, a U or other shaped tube may be used toensure unidirectional movement of water from upper compartment 33 to thelower compartment 35 of the tank. This arrangement ensures bettercleanliness environment in the upper compartment 33 which houses thepotable grade water for supply to consumers. The water tank may alsohave a siphoning facility 36 to supply water to consumers. The waterinlet 24 may be constructed with multiple openings or pores so as todischarge jets of inlet water at different points on the second inclinedfloor 32 of the tank 20, thereby helping to dislodge impurities adheringat the second inclined floor 32 and transferring them to the lowercompartment 35. Thus, potable grade clean water from the uppercompartment 33 is provided to the consumers via the consumer supplyoutlet 25, while the water from the lower compartment 35, which comesout from the draining outlet 22, may be extended and connected to anetwork of secondary uses like toilet cisterns, washing machines, floorsand driveway cleanings, gardening etc. The sensor mechanism 29 is thereto activate the pump at the right moment to replenish whatever waterlevel falls to a pre-determined level at the upper compartment 33 tomaintain supply of potable grade water to consumers.

In another preferred embodiment of the present invention, as shown inFIG. 2C, the water tank, in addition to the one shown in FIG. 2B anddiscussed in the preceding paragraph, additionally has a floating ballstopper 42 to stop water passing through second draining outlet 34. Thelower compartment 35 below the second inclined floor 32 holds the waterkept in reserve for fire fighting eventualities, should the occasionarise. This reserve has always to be maintained at full and gets waterfrom the second draining outlet 34. The upper compartment 33 locatedabove the second inclined floor 32, which receives fresh water throughinlet 24, serves to supply fresh potable grade water to consumers andgets maintained regularly through renewal of its water content in themanner as discussed above. In this embodiment, the draining outlet 22 atthe bottom of the lower compartment 35, may, like in previousembodiment, preferably, be connected to a network of secondary uses liketoilet cisterns, floor cleaning outlets, gardening terminals, cleaningof driveway etc. and may be, for cloth washing terminals as well. In theprocess, the inclined floor 21 is getting cleared of impurities andsediments substantially, as water in the surrounding spaces finds wayout through the draining outlet 22. The space getting so vacated in thelower compartment 35 gets automatically filled simultaneously from theupper compartment 33 through second draining outlet 34, just to bestopped by the stopping mechanism 42 when the lower compartment 35 isfilled to its capacity. In the process the second inclined floor 32 toogets cleared of impurities and sediments to a fairly good extent.

In FIG. 3, the water tank 20 of the present invention is shown on thetop of a building 30. Here its draining outlet pipe has been extendedand brought along the height of the building of several floors down tothe ground level. Its stop cock 27 is accessible from the ground leveland can be operated from there itself and is close to pump room 31housing the pump which supplies water to the tank 20.

FIG. 4 shows another preferred embodiment of the present invention inwhich the water tank 20 is filled with water up to level 26. The waterinlet is depicted by 24, the overflow outlet by 23, and the supplyoutlet for consumers by 25. Here the bottom of the tank is inclined fromall the sides somewhat into a funnel shape converging at 22 theconverging point of the cone, thereby providing a conical floor 48,where draining outlet pipe 30 is attached. Said outlet 30 extends to aconvenient place from where the draining process can be carried outcomfortably at regular intervals through the stop cock 27.

In another preferred embodiment of the present invention, as shown inFIG. 4A, the water tank, in addition to the one shown in FIG. 4 anddiscussed in the preceding paragraph, has a sensor mechanism 29 near themidlevel of the water tank, while the consumer supply outlet 25 islocated near a level which is around the level of the sensor mechanism29 which activates the pump to inject fresh water as soon as the levelof water inside the tank falls below a pre-determined level. Thedraining outlet 22 is provided at the convergence of the conical floor48 which may be extended and connected to a network of secondary useslike toilet cisterns, washing machines, floors and driveway cleanings,gardening etc. The sensor mechanism 29 is there to activate at the rightmoment to replenish whatever water mass finds way out of the drainingoutlet 22 and maintaining the reserve as per the requirement. Consumerscontinue to receive potable grade water through the consumer outlet nearthe midlevel of the tank. The water inlet 24 may be constructed withmultiple openings or pores so as to discharge jets of inlet water atdifferent points on the conical floor 48 of the tank occasionally afterswitching off the sensor mechanism 29 for complete evacuation of water.thereby helping to dislodge the impurities adhering to the bottom of thetank more reliably. A substantial improvement in level of cleanliness isachieved from this arrangement in comparison with that of theconventional tank of FIG. 1 because dirt and impurities do not get anopportunity to accumulate but are let out through draining outlet 22 ofthe conical floor 48 progressively.

In another preferred embodiment of the present invention, as shown inFIG. 4B, the water tank, in addition to the first conical floor 48located at the bottom of the tank, as shown in FIG. 4A and discussed inthe preceding paragraph, the tank 20 is provided with a second conicalfloor 48′ in the mid way of the vertical height of the water tank butbelow the level of the sensor mechanism 29. The second conical floor 48′is located above the first conical floor 48 that divides the tankbroadly into two compartments, namely, upper compartment 33 and lowercompartment 35, one above the other. The consumer supply outlet 25 islocated at a level above the starting end of the second conical floor48′. A second draining outlet 50, which is located at the convergence ofthe second conical floor 48′ is capable of draining out completely thewater content from the upper compartment 33 down to the lowercompartment 35 so created. Thus, the upward movement of water andimpurities etc. is mostly curtailed to a minimum which can happen onlythrough the second draining outlet 50, which is a small hole. Thissecond draining outlet 50 may be just a simple opening, as shown in FIG.4B, or a check valve to allow only unidirectional downward flow.Alternatively, a U-shaped tube may be used to ensure movement of thecontents of the upper compartment 33 to the lower compartment 35 and toprevent the reverse flow. This arrangement discourages vertical movementof water and impurities in the upward direction and ensures bettercleanliness environment in the upper compartment which holds the potablegrade water for supply to consumers. The water tank may also have analternative siphoning facility 36 to supply water to consumers. Thewater inlet 24 may be constructed with multiple openings or pores so asto discharge jets of inlet water at different points on the secondconical floor 48′ of the tank 20, occasionally after switching off thesensor mechanism 29 for complete evacuation of water from uppercompartment 35, thereby helping to dislodge impurities adhering to thesecond inclined floor 48′ more reliably and transferring them to thelower compartment 35. Thus, potable grade clean water from the uppercompartment 33 is provided to the consumers via the consumer supplyoutlet 25, while the water from the lower compartment 35, which comesout from the draining outlet 22, may be extended and connected to anetwork of secondary uses like toilet cisterns, washing machines, floorsand driveway cleanings, gardening etc. The sensor mechanism 29 is thereto activate at the right moment to replenish whatever water mass findsway out of the draining outlet 22 and maintaining the reserve as per therequirement.

In another preferred embodiment of the present invention, as shown inFIG. 4C, the water tank, in addition to the one shown in FIG. 4B anddiscussed in the preceding paragraph, additionally is provided with afloating ball stopper 42 to stop water passing through second drainingoutlet 50 when the lower compartment 35 is full. The lower compartment35 below the second conical floor 48′ holds the water kept in reservefor fire fighting eventualities, should the occasion arise. This reservehas always to be maintained at full and gets water from the seconddraining outlet 50. The upper compartment 33 located above the secondconical floor 48′, which receives fresh water through inlet 24, servesto supply fresh potable grade water to consumers continuously throughrenewal of its water content in the same manner as discussed above. Inthis embodiment, the draining outlet 22 at the bottom of the lowercompartment 35, may, like in previous embodiment, preferably, beconnected to a network of secondary uses like toilet cisterns, floorcleaning outlets, gardening terminals, cleaning of driveway etc. and maybe, for cloth washing terminals as well. In the process, the firstconical floor 48 is getting cleared of impurities and sedimentssubstantially, as water in the surrounding spaces finds way out throughthe draining outlet 22. The space getting so vacated in the lowercompartment 35 gets automatically filled from the upper compartment 33through second draining outlet 50, just to be stopped by the stoppingmechanism 42 when the lower compartment 35 is filled to its capacity. Inthe process the second conical floor 48′ too gets cleared of impuritiesand sediments to a fairly good extent. Near total cleaning of thesloping floor is achieved regularly or whenever desired through completeevacuation of the upper compartment through its draining outlet 50 andallowing falling water through inlet 24 to impact on the second conicalfloor 48′ in the upper compartment 33. A suitably long handle brush mayalso be used to further clean the conical floor in the uppercompartment. In one embodiment, the upper floor may be a conical floorwhile the lower floor may be an inclined floor and vice versa.

FIG. 5 shows a water tank according to still another embodiment of theinvention, wherein the water inlet(s) is/are located so as to dischargethe inlet water jets at different points on the inclined surface(s) ofthe conical bottom of the tank.

FIG. 6 shows a water tank according to still another embodiment of theinvention, wherein the water inlet(s) is/are located so as to dischargethe inlet water jets at different points on the inclined surface of thebottom of a rectangular or cylindrical tank.

The funnel shape of the tank helps to draw the water with any suspendedmaterial inside the tank towards the convergence point 22 when thedraining outlet 30 is opened for draining out the contents of the tank.Flow convergence coupled with gravity plays a prominent role relative toa situation where the draining outlet is situated on the periphery orelsewhere. When the tank is filled, all the dirt and foreign matter aredirected towards the outlet 22. This helps in draining out thecontaminated water and clean the tank.

It can be seen that as the conventional water tank 10 of FIG. 1 and FIG.1A is filled everyday, the sediments or foreign matter start depositingfrom day one. It adds up everyday and over a period of time forms asludge like layer 15 at the floor of the tank. The cleaning process ofsuch water tank being lengthy, time taking, labour intensive one,requires some preparation and advance planning to carry out the same andthe supply of water from this tank requires to be discontinued duringthe process. The cleaning process in such conventional tank is carriedout at fairly longer intervals because the aforesaid difficulties tendto delay the job. For this long period, the users consume everyday,progressively more dirtier water.

In sharp contrast, the proposed water tank 20 provides comparativelymuch higher level of cleanliness in water which is almost like the freshwater that is filed into the tank everyday due to the fact that theforeign matter in water does not get enough time to deposit at theinclined bottom 21 due to the slope and is regularly drained out throughthe outlet 22 situated at its lowest point at the end of the slope. Thisdraining out of all contaminated water can be carried out as frequentlyas desired because this requires only opening and closing of a tap,which even a child can do. In order to make the job still moreconvenient, the said draining outlet can be extended to a lower floor ofconvenience closer to the pump, even to the ground level as in FIG. 3and the stop cock 27 fitted there to enable cleaning of the overheadtank before pumping fresh water into the tank.

A typical action for maintenance of this proposed water tank may be tofirst drain out the contents of the tank by opening the stop cock 27.When it is fully empty the pump is started. Water starts falling on thefloor of the tank through the inlet 24 which dislodges most of thesediments and deposits on the sloping floor of the bottom of the tankthat drains out through the outlet 22 or 30, as the case may be.Occasionally, at long intervals, a sponge or cloth like cleaner or brushattached to a long handle can be used to rub out clean the bottom andwalls of the tank, if so desired, followed by letting inlet water toflow in for a few minutes to clear these materials and finally the stopcock of the said draining outlet is closed. The tank is then ready tofill with fresh clean water.

In the embodiment of the invention illustrated in FIG. 5, the waterinlet(s) is/are so located as to discharge the inlet water on theinclined surface(s) of the conical bottom of the tank.

It is also observed that a slope of around 15 to 25 degrees to thehorizontal of the inclined bottom appears fairy workable for theimpurities like a mixture of common soil and sand to move towards thedraining outlet if the tank is made of metal. A larger angle willobviously result in a more favourable flow pattern. The material andsurface qualities and conditions of the inclined bottom of the tank andthe nature of impurities or sediments are also factors that determinethe extent of slope for the inclined bottom to make the operationsmooth.

This process of complete renewal of water is carried out regularly. As aresult, the level of dirt in water is not allowed to rise byaccumulation over a period of time. This is in contrast with the currentscenario where in a conventional water tank the level of dirt keeps onrising everyday progressively till it is cleaned after a long interval.The level of cleanliness in the invented water tank always remains veryhigh and it very rarely requires a thorough cleaning.

The present invention helps to realize the following advantages:

-   -   i) The level of dirtiness in the water tank according to the        invention remains always at a very low level as compared to a        conventional tank, which requires an extensive and expensive        cleaning.    -   ii) The draining out of the contents of the water tank of the        present invention is extremely simple and can be carried out        regularly and as frequently as desired.    -   iii) The regular draining out of the content of the water tank        of the present invention does not require additional manpower        nor any special equipments or arrangement for the purpose and        without any long disruption of water supply as in the case of        conventional water tank cleaning.    -   iv) Storage of potable grade and non potable grade waters along        with their outlets getting separated in the tank itself makes it        possible that their transit and entry into kitchens, wash basins        etc. are too separated from that of toilet cisterns etc., linked        to W.C. ultimately. This eliminates any possibility of hygiene        and sanitation problems arising out of present methods of single        transit and entry of water for all those utilities.    -   v) The cost, time and labour involved in maintenance and        cleaning the proposed tank is comparatively very low.    -   vi) The resultant health and hygiene benefits for consumers are        enormous.

1. A readily cleanable dual purpose water storage system comprising: anoverhead water tank for storing water; and a pump for pumping water froma water supply source to the overhead water tank for storage of waterbefore supply to the consumers, wherein said water tank comprises: afirst inclined floor at the bottom of the tank, wherein the firstinclined floor is inclined at a pre-determined continuous and effectiveslope towards another point on the periphery to form an inclined floor;a second inclined floor located above the first inclined floor at apredetermined height, thereby dividing the water tank into upper andlower compartments; one or more inlet(s) located near the top of theupper compartment for letting water to be filled into said tank; anoverflow outlet; a first draining outlet located at the lowest point ofthe slope of the first inclined floor, with a stop cock fitted thereto;a second draining outlet located at the sloping end of the secondinclined floor such that water and impurities from the upper compartmentmoves down to the lower compartment; and a consumer supply outletlocated at the side wall above the starting end of the second inclinedfloor through which water is supplied to consumers; wherein the uppercompartment holds potable grade water for supply to consumers and thewater in the lower compartment, which comes out of the first drainingoutlet, is (a) reserved for fire fighting needs and (b) used for othernon-potable purposes with simultaneous replenishment from the uppercompartment.
 2. The water storage system of claim 1, wherein saidinlet(s) is/are provided with multiple openings or pores to dischargejets of inlet water at different points of the second inclined floor ofthe tank during periodic evacuation of the upper compartment of the tankby opening the first draining outlet, thereby helping to dislodge theimpurities adhering to the bottom of the second inclined floor of thetank more reliably, which are eventually transferred to the lowercompartment through the second draining outlet.
 3. The water storagesystem of claim 1, wherein the water storage system comprises sensormechanism(s) located at the upper compartment which is adapted toactivate the pump to inject fresh water into the water tank whenever thelevel of water inside the water tank falls below a predetermined leveland to switch off the pump when the rising water level inside the watertank reaches the pre-determined level.
 4. The water storage system ofclaim 3, wherein the sensor mechanism is switched off during completeevacuation of the tank for periodic cleaning.
 5. The water storagesystem of claim 1, wherein the second draining outlet is wide enough tosimultaneously fill the lower compartment to constantly maintain areserve level therein, wherein the second draining outlet is a U orother shaped tube to ensure unidirectional flow of water from the uppercompartment to the lower compartment.
 6. The water storage system ofclaim 1, wherein a check valve may be provided at the second drainingoutlet to ensure unidirectional flow of water from the upper compartmentto the lower compartment.
 7. The water storage system of claim 1,wherein the lower compartment reserves water for fire fightingeventualities which may be used for other non-potable use such as toiletcisterns, washing machines, floors and driveway cleanings, gardening etcwith simultaneous replenishment from upper compartment.
 8. The waterstorage system of claim 1, wherein a floating ball stopper is attachedto the second draining outlet to stop water from passing through thesecond draining outlet when the lower compartment is filled to itscapacity.
 9. A readily cleanable dual purpose water storage systemcomprising: an overhead water tank for storing water; and a pump forpumping water from a water supply source to the overhead water tank forstorage of water before supply to the consumers, wherein said water tankcomprises: a first conical floor at the bottom of the tank, wherein thefirst conical floor is inclined at a pre-determined continuous andeffective slope from all sides to form a conical bottom; a secondconical floor located above the first conical floor at a predeterminedlevel, thereby dividing the water tank into upper and lowercompartments; one or more inlet(s) located near the top of the uppercompartment for letting water to be filled into said tank; an overflowoutlet; a first draining outlet located at the convergence of the firstconical floor, with a stop cock fitted thereto; a second draining outletlocated at the convergence of the second conical floor such that waterand impurities from the upper compartment moves down to the lowercompartment; and a consumer supply outlet located at the side wall abovethe second conical floor through which water is supplied to consumers;wherein the upper compartment holds potable grade water for supply toconsumers and the water from the lower compartment, which comes out ofthe first draining outlet, is (a) reserved for fire fighting needs and(b) used for other non-potable purposes with simultaneous replenishmentfrom upper compartment.
 10. The water storage system of claim 9, whereinsaid inlet(s) is/are provided with multiple openings or pores todischarge jets of inlet water at different points on the second conicalfloor of the tank during periodic evacuation of the upper compartment ofthe tank by opening the first draining outlet, thereby helping todislodge the impurities adhering to the second conical floor of the tankmore reliably, which are eventually transferred to the lower compartmentthrough the second draining outlet.
 11. The water storage system ofclaim 9, wherein the water storage system comprises sensor mechanism(s)located at a predetermined height in the upper compartment which isadapted to activate the pump to inject fresh water into the water tankwhenever the level of water inside the water tank falls below apredetermined level and to switch off the pump when the water levelinside the water tank reaches the pre-determined level.
 12. The waterstorage system of claim 11, wherein the sensor mechanism is switched offduring complete evacuation of upper compartment of the tank for periodiccleaning.
 13. The water storage system of claim 11, wherein the seconddraining outlet is wide enough to simultaneously fill the lowercompartment to constantly maintain a reserve level therein, wherein thesecond draining outlet is a U or other shaped tube to ensureunidirectional flow of water from the upper compartment to the lowercompartment.
 14. The water storage system of claim 11, wherein a checkvalve may be provided at the second draining outlet to ensureunidirectional flow of water from the upper compartment to the lowercompartment.
 15. The water storage system of claim 11, wherein the lowercompartment reserves water for fire fighting eventualities which is usedfor other non-potable use such as toilet cisterns, washing machines,floors and driveway cleanings, gardening etc with simultaneousreplenishment from upper compartment.
 16. The water storage system ofclaim 11, wherein a floating ball stopper is attached to the seconddraining outlet to stop water from passing through the second drainingoutlet when the lower compartment is filled to its capacity.
 17. Areadily cleanable dual purpose water storage system comprising: anoverhead water tank for storing water; and a pump for pumping water froma water supply source to the overhead water tank for storage of waterbefore supply to the consumers, wherein said water tank comprises: afirst inclined floor at the bottom of the tank; a second inclined floorlocated above the first inclined floor at a predetermined height,thereby dividing the water tank into upper and lower compartments; oneor more inlet(s) located near the top of the upper compartment forletting water to be filled into said tank; an overflow outlet; a firstdraining outlet located at the lowest point of the first inclined floor,with a stop cock fitted thereto; a second draining outlet located at thelowest point of the second inclined floor such that water and impuritiesfrom the upper compartment moves down to the lower compartment; and aconsumer supply outlet located at the side wall above the secondinclined floor through which water is supplied to consumers; wherein theupper compartment holds potable grade water for supply to consumers andthe water from the lower compartment, which comes out of the firstdraining outlet, is (a) reserved for fire fighting needs and (b) usedfor other non-potable purposes with simultaneous replenishment from theupper compartment.
 18. The water storage system of claim 17, wherein thefirst inclined floor is a conical floor at the bottom of the tank withthe first draining outlet being located at the convergence of theconical bottom and the second inclined floor is inclined at apre-determined continuous and effective slope towards another point onthe periphery to form a sloping floor with the second draining outletbeing located at the lowest point of the sloping floor.
 19. The waterstorage system of claim 17, wherein the first inclined floor is inclinedat a pre-determined continuous and effective slope towards another pointon the periphery to form a sloping floor at the bottom of the tank withthe first draining outlet being located at the lowest point of thesloping floor and the second inclined floor is a conical floor with thesecond draining outlet being located at the convergence of the conicalbottom.